Ocean aquaculture requires significant infrastructure, such as pens to contain fish and barges to perform husbandry functions. Other activities in the ocean or other bodies or water—such as habitation, research platforms or military purposes—also require infrastructure that is held on a mooring in a robust, semi-rigid fashion. This infrastructure is generally secured using taut-line mooring systems. A multi-point taut-line mooring system is usually used to secure infrastructure. Multi-point taut-line mooring systems offer the advantage of being able to hold infrastructure in a fixed location, with each moored element a fixed distance apart. The fixed relationship of space between infrastructure assets prevents collisions and tangling, and allows scaling of the infrastructure within a limited geographic proximity. The tension of the mooring lines holds the objects or vessels in place, relative to each other. Grid-lines may allow multiple objects or vessels to be held in close proximity. The fixed residual buoyancy points of a multi-point taut-line mooring system also allow for submergence of any object to a pre-determined depth, depending on the length of the bridle lines from the object to the residual buoyancy point. However, multi-point taut-line mooring systems are highly complex, expensive, often infeasible for securing infrastructure in deep waters, and do not allow the array to orient along a single axis into the current.
Single-point mooring systems have been used to secure infrastructure in deeper waters. Single-point mooring systems in use up to this point, however, do not hold infrastructure in a fixed location, as the floating infrastructure will change positon according to wind and currents, within an umbra or “watch circle” as dictated by the length of the mooring rode, and conventionally could not allow for ready submergence of objects, without risk of collision, entanglement or other problematic interaction. Slack-line moorings and unmoored objects also present similar risks of collision and entanglement, and do not allow objects to be readily submerged at a set depth separate from the residual buoyancy. Thus, multiple infrastructure assets each on a single point or slack-line mooring, or adrift unmoored in a limited geographical proximity have a risk of colliding with each other, or of tangling the bridle lines. Such collisions or entanglements can destroy infrastructure and are normally avoided by not allowing multiple objects on single-point or slack-line moorings, or on unmoored arrays.
Thus the inability of single and multi-point slack-line mooring systems and unmoored arrays to accommodate cost effective deployment of scalable offshore infrastructure is a significant drawback.